Extrusion press



May 28, 1968 A. WALKER EXTRUSION PRESS 3 Sheets-Sheet 1 Filed Feb. 1, 1966 E 0 W w N L A m .-.W

y 1968 A. R. WALKER 3,385,090

EXTRUSION PRESS Filed 1966 I 3 Sheets-Sheet 2 AR. WALKER- BY y 1968 A. R. WALKER 3,385,090

EXTRUSION PRESS Filed Feb. 1, 1966 3 Sheets-Sheet 5 \NvENToR A. R WALKER J-ldejlqu *fim uLvis ATTORNEYS 8,385,091) EXTRUSION PRESS. v Arthur Raymond Walker, Winton, Bournemouth, England, assignor to Davy and United Engineering Company Limited, Sheffield, Yorkshire,E'ngland" Filed Feb. 1, 1966,Ser. No. 524,287 7 Claims. (Cl. 72-263) ABSTRACT OF THE DISCLOSURE The invention relates. to extrusion presses provided with rotatable die-change apparatus positioned to one side of the press away from the'press axis and having two die-holding arrangements. The die to be replaced may be moved from its support in the press into one of the holding arrangements and a replacement die positioned in the other holding arrangement. The apparatus may then be rotated until the replacement die is so positioned that it can be easily moved into the press.

This invention relates to apparatus for changing the dies of extrusion presses and to presses incorporating such apparatus.

In a previous arrangement for die changing in extrusion presses, the die to be changed, together with its holder, is moved in first guides laterally of the press center line into further guides normal to the first guides, and is then moved in these guides away from alignment with the first guides. The latter movement also brings a replacement die into line with the first guides, and the replacement die is then moved along the first guides into position in the press. With this arrangement the position of the die that has been removed from the press is too high for normal access, and the mechanism itself provides unnecessary hazards for the operator during the die-changing operation.

In another previous arrangement, a cylindrical die in a rectangular die holder is moved in guides laterally of the press holder by means of a latch which sometimes serves the dual purpose of locking the die in position in the holder as well as ejecting it therefrom. Upon ejection the cylindrical die is lowered or is permitted to roll down an inclined surface by a ram. With this arrangement it is extremely difiicult to ensure that the die orific is properly orientated when the die reaches the press, since the die can rotate whilst it is being moved into the die holder. Furthermore the presence of the locking and ejecting latch can prove inconvenient.

In a further previous arrangement of a die changing mechanism for an extrusion press, a rotary die housing is located within the press, and die stations in the housing pass across the die position in the press. With this arrangement the essential dimensions of the housing make it necessary for the columns of the press to be more widely spaced than would otherwise be the case, so that the design is expensive.

In yet a further previous arrangement a die slide hav- I ing two dies is arranged to move laterally of the press centre line, and one die is removed from the slide on one side of the press whilst the other die is removed from the slide on the other side of the press, This arrangement, of course, requires that access to the press at the die-changing station must be had on both sides of the press.

According to one aspect of the invention there is provided apparatus for changing the die of an extrusion press comprising a die-receiving structure mounted for rotation between two positions in each of which a different one of the die holding arrangements of the structure is presented at a die-receiving position, each said 3,385,090 Patented May 28, 1968 ICC holding arrangement including locating means for cooperation witha die held therein to ensure positive loction of the die with the orientation required for correct positioning in the press.

According to another aspect of the invention there is provided an extrusion press having disposed outside the area lying between the columns of said press a rotatable die changing apparatus having at least two die-holding arrangements, means for displacing the die assembly of the press radially of the center line of the press into register with a die-holding arrangement of the die changing apparatus, means for releasing a die so displaced from the press and moving it into said die-holding arrangement, and means for rotating said apparatus to bring a second die holding arrangement into register with the displaced position of the die assembly, each said die-holding arrangement including means for locating a die therein with an orientation appropriate to its transfer into correct location within the die assembly of the press.

The following description relates to the accompanying drawings which show, by way of example only, one embodiment of a die-changing mechanism according to the invention.

Of the drawings:

FIGURE 1 is a vertical section through an extrusion press with a rotatable die-changer indicated in chain line,

FIGURE 2 is an enlarged view of the rotatable diechanger in greater detail,

FIGURE 3 is a view in the direction of the arrow III in FIGURE 2, and

FIGURE 4 is a diagram showing the mode of die displacement.

In FIGURE 1 the extrusion press shown has four columns 11 supporting a platen 12 which carries a die slide-block 13 holding a cylindrical die 14 in a part cylidrical surface 13A in which is located a key 1313 co-operating with a key-way in the die 14. The die slide-block is slidably guided in horizontal guides 15 arranged normal to the press center-line indicated at 16. A piston and cylinder arrangement 17 and 18 is provided to move the die slide-block along the guides 15.

A rotatable die-changer 19, best shown in FIGURES 2 and 3, is located outside the area defined by the axes of the press columns 11 and is carried on an extension 20 of the platen 12. The changer 19 has two positions for supporting dies and these are provided by parts cylindrical surfaces 21 each extending over an arc of more than and having keys 13C and 13D similar to the key 13B in the die holder. The keys 13C and 13D are each located in a shoe 22, one only of which is shown, the shoes being pivotable about shafts 23 into and out of engagement with a die 14 as shown in chain lines and solid lines respectively, by a linkage 24 having a hand operated lever 25.

The rotatable die-changer has pairs of bifurcated arms such as 26, 27 arranged one at each end of the part cylindrical surface 21, and the arms are supported on shafts 28 along which they are slidable by means not shown.

Referring to FIGURE 4, in operation, assuming that a die is in position 14 in. the press, and a replacement die is in position 14C with the shoe 22 (FIGURE 2) in the closed position in chain lines, and the arms 26 and 27 (FIGURE 2) adjacent the press are positioned in alignment with the die slide-block 13 to receive the die therefrom between them.

The piston and cylinder mechanism 17, 18 (FIGURE 1) is actuated to move the die slide-block 13 so that the die takes the position 14A in FIGURE 4, between the arms 26 and 27. The arms 26 and 27 are then actuated to slide the die axially out of the die slide-block 13 and into the position 14B in the rotatable die-cl1anger. The diechanger is rotated 180 to interchange the position of the dies at 14B and 14C, and the arms 26, 27 are actuated in reverse to slide the die now in position 14B into position 14A. The die slide-block is then traversed to bring the die to position 14 and the die changing operation is complete.

If it is then required to move the die from position 14C in the rotatable die-changer, the hand lever 25 is moved upwardly to the position shown in full lines in FIGURE 2, thus raising the shoe 22 and reducing the are of contact of the die-changer with the die to less than 180 so that the die may be lifted clear.

With the arrangement described, at all times during the die-changing cycle, the die is secure either in the die slide-block or between the bifurcated arms in cooperation with the die slide-block and/or the supporting surfaces in the rotatable die-changer, so that there is no danger of the die or any part thereof falling out.

The provision of the keys 13 in the rotatable diechanger and in the die slide-block ensures that the die extrusion orifice is correctly orientated when in the press.

The die-change arrangement described affords access to the die when it is in either of the positions in the rotatable die-changer, so that any dressing of the die could be done in either of these positions if required. Furthermore, when a die is in the rotatable die-changer in the position remote from the press, it is sutiiciently far away from the press itself to enable the operator to work on the die without undue discomfort from the heat of the container.

I claim:

1. An extrusion press comprising:

an exrusion die supporting means,

press means,

a plurality of columns connecting the die supporting means to the pressing means,

a die carrier mounted for movement radially of the center line of the press between a pressing position in which it is supported by said die supporting means in line with said center line and a die change position,

a rotatable die cehanging apparatus positioned outside the area lying between the columns and having two die-holding arrangements mounted for alternate alignment with the die carrier in its die change position, and

means for moving a die in a direction parallel to the center line of the press out of said die carrier in its die change position and into the die holding arrangement aligned therewith, and vice versa.

2. An extrusion press as claimed in claim 1 wherein each said die-holding arrangement includes a pair of bifurcated arms arranged to support and guide a die in its movement into and out of said arrangement.

3. An extrusion press as claimed in claim 2 wherein said arms are slidably arranged for movement with a die entering or leaving said arrangement.

4. An extrusion press comprising:

an extrusion die supporting means,

pressing means,

a plurality of columns connecting the die supporting means and the pressing means,

a die carrier mounted for movement radially of the center line of the press between a pressing position in which it is supported by said die supporting means in line with said center line and a die change position, and

a rotatable die changing apparatus positioned outside the area lying between the columns and having two die-holding arrangements mounted for alternate alignment with the die change position of the die carrier, each die holding arrangement including means for locating a die therein with an orientation appropriate to its transfer into correct location with the die carrier.

5. An extrusion press as claimed in claim 4 in which the locating means comprises cooperating keys and keyways on the dies, die carrier and die-holding arrangements.

6. An extrusion press as claimed in claim 5 wherein each said die holding arrangement comprises a partcylindrical surface extending over more than 180, at least part of which is constituted by a pivotable shoe carrying said key and arranged to be pivoted away from the remainder of the surface so as to provide an entry aperture for a die which is not obstructed by said key and to be pivoted toward the remainder of said surface for positioning of said key in the keyway of a die received in said holding arrangement.

7. Apparatus for changing the die of an extrusion press comprising a die-receiving structure mounted for rotation between two positions in each of which a different one of two die holding arrangements of the structure is presentcd at a die receiving position, and

means for moving a die axially between one of the dieholding arrangements at the die-receiving position and a die carrier, with each said holding arrangement including locating means for cooperation with a die held therein to ensure positive location of the die with the orientation required for correct positioning in the press.

References Cited UNITED STATES PATENTS 3,139,183 6/1964 Elkan et al 72-263 3,175,384 3/1965 Gross et a1 72-263 FOREIGN PATENTS 1,152,084 8/1963 Germany.

729,263 5/1955 Great Britain.

CHARLES W. LANHAM, Primary Examiner.

K. C. DECKER, Assistant Examiner. 

